Formula and Molecular Mass

Question

How many µL of 5.00% acetic acid by mass would you need to provide 3.41 x 10²⁰ C atoms? (Assume the density of the solution is 1.011g/mL)

Answer 1

5% acetic acid by mass = 5 g acetic acid/100 mls solution

Formula for acetic acid is CH3COOH = C2H4O2 (note: 2 moles of C per mole acetic acid)

3.41x10²⁰ C atoms x 1 mole C atoms/6.02x10²³ C atoms = 5.66x10^-4 moles C atoms

5.66x10^-4 moles C x 1 mole C2H4O2/2 moles C = 2.83x10^-4 moles C2H4O2

molar mass C2H4O2 = 60 g/mole

2.83x10^-4 moles x 60 g/mole = 170 g

170 g x 1 ml/1.011 g = 168 ml